Pension And Other Postretirement Benefits (Schedule Of Defined Benefit Plans Disclosures) (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Net Unfunded Status of Plans [Roll Forward]
Net funded status before tax adjustments	$ (64,463)	$ (91,182)		$ (91,182)
Service cost	(2,078)	(2,079)	$ (1,807)	(4,157)	$ (3,615)
Interest cost	(7,408)	(7,408)	(7,789)	(14,816)	(15,577)
Expected return on assets	11,206	11,206	10,473	22,412	20,946
Employer contributions during quarter		25,000
Net funded status before tax adjustments	(62,743)	(64,463)		(62,743)
Regulatory Assets Related to Pensions [Roll Forward]
Regulatory assets before tax adjustments	232,200	236,891		236,891
Amortization of prior service cost	(1,217)	(1,216)	(1,213)	(2,433)	(2,426)
Amortization of net actuarial loss	(3,475)	(3,475)	$ (2,426)	(6,950)	$ (4,855)
Regulatory assets before tax adjustments	$ 227,508	$ 232,200		$ 227,508